使用STC89C52RC输出PWM调节LED亮度

以下是STC89C52RC控制PWM调节LED亮度的代码：

#include <reg52.h>

#define FOSC 11059200L //晶振频率
#define T1MS (FOSC/12/1000) //1ms定时器值

sbit LED = P1^0; //LED接口

void Timer0Init()
{
TMOD |= 0x01; //选择为定时器0模式，工作方式1，仅用TR0打开启动。
TH0 = 0xFC; //给定时器赋初值，定时1ms
TL0 = 0x67;
ET0 = 1; //打开定时器0中断允许
EA = 1; //打开总中断允许
TR0 = 1; //打开定时器
}

void main()
{
Timer0Init();
while(1)
{
LED = ~LED; //LED翻转
delay_ms(500); //延时500ms
}
}

void Timer0() interrupt 1
{
static unsigned char cnt = 0;
static unsigned char pwm = 0;

TH0 = 0xFC; //给定时器赋初值，定时1ms
TL0 = 0x67;

cnt++; //计数器自增

if(cnt == 100) //计数值为100时重置为0
{
cnt = 0;
}

if(cnt < pwm) //当计数值小于占空比pwm时，LED亮
{
LED = 0;
}
else //否则LED灭
{
LED = 1;
}
}

void delay_ms(unsigned int ms)
{
unsigned int i,j;
for(i=0;i<ms;i++)
{
for(j=0;j<T1MS;j++);
}
}